Methods for controlling a traffic of an authentication server

ABSTRACT

A method for controlling the traffic of an authentication server and an authentication access apparatus, wherein a local area network token bucket including a high priority token bucket and a low priority token bucket is set according to the capability of the authentication server in processing the request message, and the request message sent by the authentication client is redirected to the authentication server after allocating a token to the authentication client, thus the traffic of the authentication server is controlled, so that the authentication server will not receive more request messages than it can handle. Meanwhile, the tokens in the high priority token bucket are reserved specially for authentication clients of a high priority, and they cannot be used by authentication clients that are not of a high priority, so the quality of service for authentication clients of a high priority is improved.

BACKGROUND

In order to enhance security control and operation management of network resources, it is necessary to control users' access to networks. For example, in network access points of some public places, residential areas or corporations, the access service providers may wish to allow access only by the paying users. Another example is that some enterprises may provide some internal key resources for access by some special users. The technique of authentication emerges in order to realize access controls mentioned above.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the Portal deployment of a district/office building according to an example;

FIG. 2 is a flow chart of a method for controlling a traffic of an authentication sever according to an example;

FIG. 3 is a schematic diagram of the setting of a token bucket according to an example;

FIG. 4 is a flow chart of the method for controlling the Portal server traffic according to an example;

FIG. 5 is a structural schematic diagram of the authentication access apparatus according to an example;

FIG. 6 is a structural schematic diagram of the authentication access apparatus according an example.

DETAILED DESCRIPTION

An authentication system usually includes an authentication client, an authentication server, an authentication access device and an Authentication Authorization Accounting (AAA) server. An authentication server may serve one or more local area networks, and one authentication access device may also serve one or more local area networks, while the specific relationships of an authentication server and local area networks as well as an authentication access device and local area networks may be set according to requirements of a specific application.

Now a method of authenticating a user will be described by taking the Portal authentication technique as an example.

The Portal authentication technique provides a flexible way of access control, which directly uses the WEB page for authentication without requiring additionally deployed clients.

It is supposed that a district or an office building is a local area network, and different enterprises in the district or office building are different sub local area networks in the local area network. FIG. 1 is a schematic diagram of the Portal deployment of a district/office building according to an example, which comprises: a Portal server 101, Portal clients 1021, 1022, 1031, 1032, a Broadband Access Server (BAS) 104 and an AAA server 105, wherein, the Portal server 101 is a service end system that accepts authentication requests in the Portal networking, the Portal client 1021 or 1022 provided in enterprise A 102 and the Portal client 1031 or 1032 provided in enterprise B 103 are client systems that initiate an authentication request in the Portal networking, which are actually browsers that run Hypertext Transfer Protocols (HTTPs) on users' terminal devices, and the BAS 104 is an authentication access device in the Portal networking.

The components shown in FIG. 1 perform the authentication operations as follows:

First, an un-authenticated Portal client 1021, 1022, 1031 or 1032 accesses a network 107 and sends a request message. The BAS 104, after parsing that the request message is sent by an un-authenticated Portal client 1021, 1022, 1031 or 1032, returns to the Portal client 1021, 1022, 1031 or 1032 the address of the Portal server 101. And then, the Portal client 1021, 1022, 1031 or 1032 re-sends the request message to the Portal server 101.

After the above-mentioned operations, the request message (i.e., HTTP request) of the Portal client 1021, 1022, 1031 or 1032 is redirected to the Portal server 101 through the BAS 104.

Subsequently, the Portal client 1021, 1022, 1031 or 1032 writes authentication information on a WEB authentication page provided by the Portal server 101 and submits it. The Portal server 101 then sends the authentication information to the BAS 104. The BAS 104 interacts with the AAA server 105 and authenticates, authorizes and bills the Portal client 1021, 1022, 1031 or 1032 using the authentication information.

After passing the authentication, the Portal client 1021, 1022, 1031 or 1032 sends a request message, and the BAS 104 allows the request message to pass. In another words, the BAS 104 opens the pathway between the Portal client 1021, 1022, 1031 or 1032 and the Internet 107 to allow access to the Internet 107 by the Portal client 1021, 1022, 1031 or 1032.

Since there are many authentication clients in the local area network, if the request messages of many authentication clients are redirected to the authentication server at the same time, a traffic attacking the authentication server will be formed, which will seriously affect the performance of the authentication server, as a result, some users of a high priority may not be able to be authenticated and access the Internet resources, and the quality of service for the users of a high priority is lowered.

FIG. 2 is a flow chart of the method for controlling the traffic of an authentication sever according to an example, the method comprises:

At block 201, setting a token bucket for storing tokens first, specifically, setting a local area network token bucket including a high priority token bucket and a low priority token bucket for a local area network. The local area network token bucket is to store tokens for allocating to authentication clients in the local area network. When one authentication server serves only one local area network, the number of tokens in the local area network token bucket corresponding to the local area network is equal to the number of request messages which can be processed by the authentication server. When one authentication server serves more than two local area networks, the number of tokens in the local area network token bucket corresponding to the local area network is less than the number of request messages which can be processed by the authentication server. The specific value of the number of tokens can be flexibly configured according to the demand of the local area network.

At block 202: detecting whether an authentication client in the local area network that sends a request message is of a high priority or not, proceeding to block 203 when the authentication client has been detected to be of a high priority, and proceeding to block 204 when the authentication client has been detected to be not of a high priority.

At block 203: allocating a token from the high priority token bucket to the authentication client that sends the request message and redirecting the request message to the authentication server, and then proceeding to block 205.

At block 204: allocating a token from the low priority token bucket to the authentication client that sends the request message and redirecting the request message to the authentication server, and then proceeding to block 205

At block 205: recovering the allocated token after a successful authentication of the authentication client that sends the request message.

In addition, in one example, the setting of a local area network token bucket (i.e., a token bucket) at block 201 may be performed only one time at the beginning. Of course, in another example, the setting of a local area network token bucket (i.e., a token bucket) at block 201 may be performed at any time according to the requirements of a particular application.

It can be seen that in the method for controlling the traffic of an authentication sever according to the example, a local area network token bucket including a high priority token bucket and a low priority token bucket is set according to the capability of the authentication server in processing the request messages, and the request message sent by the authentication client is redirected to the authentication server after allocating a token to the authentication client, thus the traffic of the authentication server is controlled, so that the authentication server will not receive more request messages than it can handle. Meanwhile, the tokens in the high priority token bucket are reserved exclusively for authentication clients of a high priority, and they cannot be used by authentication clients that are not of a high priority, so the quality of service for authentication clients of a high priority is improved.

It is noted that the above-mentioned method is performed only with respect to the un-authenticated authentication clients, while as for the authentication clients that have already been authenticated or that have been preset as not requiring authentication, the above-mentioned method will not be performed, but such authentication clients that have already been authenticated or that have been preset as not requiring authentication are directly allowed access to the Internet.

The method for controlling the traffic of an authentication server is described below according to an example.

FIG. 3 is a schematic diagram of the setting of a token bucket according to an example. In the example, the authentication system is a Portal authentication system, and the local area network includes two sub local area networks. The setting of the token bucket in this example includes:

-   -   first, setting a local area network token bucket 30, in which         the number of tokens can be set flexibly, as long as it is not         beyond the capability of the Portal server in processing request         messages;     -   second, setting a shared token bucket 303 and sub local area         network token buckets 301 and 302 corresponding to each of the         sub local area networks in the local area network token bucket         30, the number of tokens in each of sub local area network token         buckets 301 or 302 being customized according to the requests,         and the sum of the numbers of tokens in each of the sub local         area network token buckets 301 and 302 and in the shared token         bucket 303 being equal to the number of tokens in the local area         network token bucket 30;     -   third, setting a high priority token bucket 3011 or 3021 and a         low priority token bucket 3012 or 3022 in each of the sub local         area network token buckets 301 and 302, wherein the number of         tokens in the high priority token bucket 3011 or 3021 is equal         to the number of Portal clients (i.e., authentication clients)         that are configured to have a high priority in the sub local         area network to which the high priority token bucket 3011 or         3021 belongs, and the sum of the numbers of tokens in the high         priority token bucket 3011 or 3021 and low priority token bucket         3012 or 3022 of a sub local area network token bucket are equal         to the number of tokens in the sub local area network token         bucket 301 or 302.

In the present example, the configuration of the Portal client of a high priority and the Portal client of a low priority includes the following two circumstances: for a three-layer Portal authentication, the Portal client is identified by an IP address, and an IP address field corresponding to each of the sub local area networks as well as the corresponding priority of each IP address in each IP address field are configured; and for a two-layer Portal authentication, the Portal client is identified by a Media Access Control (MAC) address, and a corresponding MAC address field of each of the sub local area networks as well as the corresponding priority of each MAC address in each MAC address field are pre-configured;

FIG. 4 is a flow chart of the method for controlling the Portal server traffic according to an example, the method includes as follows:

-   -   at block 401: detecting which sub local area network the Portal         client that sends the request message belongs to and the         priority of the Portal client, proceeding to block 402 if the         Portal client is detected to be of a high priority, and         proceeding to block 403 if the Portal client is detected to be         not of a high priority.

At block 401, the detection process is as follows: if it is a three-layer Portal authentication, the sub local area network to which the Portal client belongs and the priority of the Portal client are determined according to the IP address and configuration information of the Portal client that sends the request message; if it is a two-layer Portal authentication, the sub local area network to which the Portal client belongs and the priority of the Portal client are determined according to the MAC address and configuration information of the Portal client that sends the request message.

At block 402: determining the sub local area network token bucket 301 or 302 corresponding to the sub local area network to which the Portal client that sends the request message belongs, and taking a high priority token bucket 3011 or 3021 in the determined sub local area network token bucket 301 or 302 as the token bucket for allocating tokens, and then allocating a token to the Portal client that sends the request message and redirecting the request message to the Portal server, and then proceeding to block 409.

At block 402, the number of tokens in each high priority token bucket 3011 or 3021 is equal to the number of Portal clients that are configured to have a high priority in its sub local area network, so the Portal clients of a high priority will have tokens allocated thereto in any case.

At block 403, determining the sub local area network token bucket 301 or 302 corresponding to the sub local area network to which the Portal client that sends the request message belongs, and taking a low priority token bucket 3012 or 3022 in the determined sub local area network token bucket 301 or 302 as the token bucket for allocating tokens.

At block 404, judging whether there is a token in the low priority token bucket 3012 or 3022, if yes, then proceeding to block 405, otherwise, proceeding to block 406.

At block 405, allocating a token from the low priority token bucket 3012 or 3022 to the Portal client that sends the request message and redirecting the request message to the Portal server, and then proceeding to block 409.

At block 406: judging whether there is a token in the shared token bucket 303, if yes, then proceeding to block 407, otherwise, proceeding to block 408.

At block 407, allocating a token from the shared token bucket 303 to the Portal client that sends the request message and redirecting the request message to the Portal server, and then proceeding to block 409.

At block 408, discarding the request message and ending the method.

At block 409, recovering the allocated tokens after a successful authentication of the Portal client that sends the request message, and the method ends.

The recovering of the allocated token at block 409 specifically includes: re-generating a token in the token bucket allocating the token to the Portal client that sends the request message.

The process shown in FIG. 4 can be implemented in various specific application scenarios, for example, a district or an office building is considered as a local area network, and the enterprises in the district or office building are considered as different sub local area networks. Each of the enterprises may request to customize its own sub local area network token bucket as well as the high priority token buckets and low priority token bucket in the sub local area network token bucket according to the requirements of an application.

In addition to controlling the traffic of the Portal server and guaranteeing the quality of service for users of a high priority, the following further technical effects are also achieved by the process shown in FIG. 4:

1. The sub local area network token buckets are further provided in the local area network token bucket, which are independent from each other and include high priority token buckets and low priority token buckets, so that each of the sub local area networks can conveniently change the setting of the corresponding sub local area network token bucket according to the change of its own requirements without the need to request customization to the local area network administrator, for example, if the number of Portal clients that are configured to have a high priority is increased in an enterprise, then the number of tokens in the high priority token buckets of the enterprise can be increased by the administrator of the enterprise and the number of tokens in the low priority token buckets of the enterprise can be reduced by the administrator of the enterprise correspondingly;

2. Not only sub local area network token buckets but also independent shared token buckets are provided in the local area network token bucket, and since the tokens in the shared token bucket can be allocated to Portal clients that are not of a high priority in all sub local area networks, the utility rate of the Portal server resource is increased;

3. In each sub local area network token bucket, the number of tokens in the provided high priority token buckets is equal to the number of the Portal clients that are configured to have a high priority in the sub local area network, thus it is ensured that the Portal clients of a high priority can have tokens allocated thereto in any case, which further guarantees the quality of service for Portal clients of a high priority.

The above example is just an example of the method for controlling the traffic of an authentication server, but in other application scenarios, there may also be the following circumstances:

First, one high priority token bucket and more than two low priority token buckets are provided in each local area network token bucket, accordingly, the Portal clients can be configured to have a high priority or low priorities of different levels. On this basis, the process of implementation of the method is basically the same as the process shown in FIG. 4, and the differences lie in that:

-   -   At block 403, further searching the determined sub local area         network for the low priority token bucket corresponding to the         level of the Portal client that sends the request message, and         taking the found low priority token bucket as the token bucket         for allocating tokens are performed;     -   At block 406, first judging, in the sub local area network token         bucket corresponding to the sub local area network to which the         Portal client that sends the request message belongs, whether         there is a token in other low priority token buckets whose level         is lower than that of the low priority token bucket found in         block 403, if yes, then allocating a token from the other low         priority token buckets to the Portal client that sends the         request message and redirecting the request message to the         Portal server, otherwise, performing again the judging whether         there is a token in the shared token bucket.

Second, no shared token bucket is provided in the local area network token bucket, while one high priority token bucket and more than two low priority token buckets are provided in each local area network token bucket, accordingly, the Portal clients can be configured to have a high priority or low priorities of different levels. On this basis, the process of implementation of the method is basically the same as the process shown in FIG. 4, and the differences lie in that:

-   -   At block 403, further searching the determined sub local area         network for the low priority token bucket corresponding to the         level of the Portal client that sends the request message, and         taking the found low priority token bucket as the token bucket         for allocating tokens are performed;     -   Not performing block 406, and when it is determined at block 404         that the low priority token bucket found at block 403 does not         have any tokens, and then further judging, in the sub local area         network token bucket corresponding to the sub local area network         to which the Portal client that sends the request message         belongs, whether there is a token in other low priority token         buckets whose level is lower than that of the low priority token         bucket found in block 403, if yes, then allocating a token from         the other low priority token buckets to the Portal client that         sends the request message and redirecting the request message to         the Portal server, otherwise, performing block 408 directly.

It can be seen that when providing more than two low priority token buckets in each of the sub local area network token buckets, it is allowed to preempt tokens for Portal clients corresponding to low priority token buckets of a certain level from low priority token buckets of a lower level in the same sub local area network token bucket.

Further, if it is necessary to make sure that not all the tokens in the low priority token buckets of a lower level are preempted, a token preempting threshold may be set, when the number of tokens preempted in a low priority token bucket has reached the token preempting threshold, it will not be allowed to preempt tokens from the low priority token bucket.

In addition, in some application scenarios, if several Portal clients configured to have a high priority cannot possibly need to be authenticated simultaneously, for example, some high priority users and other high priority users in an enterprise use the network resources at completely different times, the number of tokens in the high priority token buckets may be set to be less than the number of Portal clients of a high priority, thus the Portal clients of a high priority that need to be authenticated at the same time can always have tokens allocated thereto, thereby avoiding the waste caused by reserving too many tokens for the Portal clients of a high priority.

FIG. 5 is a structural schematic diagram of an authentication access apparatus according to an example, the authentication access apparatus comprises: a token bucket setting unit 501 and a detecting and allocating unit 502.

The token bucket setting unit 501 is to set a local area network token bucket including a high priority token bucket and a low priority token bucket for a local area network, wherein the number of tokens in the local area network token bucket is equal to the number of request messages which can be processed by an authentication server.

The detecting and allocating unit 502 is to detect whether an authentication client that sends a request message is of a high priority or not, when the authentication client has been detected to be of a high priority, to allocate a token from the high priority token bucket to the authentication client that sends the request message and redirect the request message to the authentication server; and when the authentication client has been detected to be not of a high priority, to allocate a token from the low priority token bucket to the authentication client that sends the request message and redirect the request message to the authentication server; and to recover the allocated token after the successful authentication of the authentication client that sends the request message.

It can be seen that in the authentication access apparatus according to the above-mentioned example, the local area network token bucket including a high priority token bucket and a low priority token bucket is set according to the capability of the authentication server in processing the request messages, and the request message sent by the authentication client is redirected to the authentication server after allocating a token to the authentication client, thus the traffic of the authentication server is controlled, so that the authentication server will not receive more request messages than it can handle. Meanwhile, the tokens in the high priority token bucket are reserved exclusively for authentication clients of a high priority, and they cannot be used by authentication clients that are not of a high priority, so the quality of service for authentication clients of a high priority is improved.

FIG. 6 is a structural schematic diagram of the authentication access apparatus according to an example. In this example, the authentication system is a Portal authentication system, and the local area network includes more than two sub local area networks.

As shown in FIG. 6, the token bucket setting unit 601 comprises: a setting execution module 6011 and a storage module 6012.

The setting execution module 6011 is to set a local area network token bucket, the number of tokens in the local area network token bucket being equal to the number of request messages which can be processed by the authentication server; to set sub local area network token buckets corresponding to each of the sub local area networks in the local area network token bucket and a shared token bucket, a sum of the numbers of tokens in each of the sub local area network token buckets and in the shared token bucket being equal to the number of tokens in the local area network token bucket; to set a high priority token bucket and a low priority token bucket in each sub local area network token bucket, wherein the number of tokens in the high priority token bucket is equal to the number of authentication clients which are of a high priority in the sub local area network and the sum of the numbers of tokens in the high priority token bucket and low priority token bucket is equal to the number of tokens in the sub local area network token bucket.

The storage module 6012 is to store the result of setting of the setting execution module 6011.

As shown in FIG. 6, the detecting and allocating unit 602 comprises: a detecting execution module 6021, a first allocating module 6022, a second allocating module 6023 and a recovering module 6024.

The detecting execution module 6021 is to detect which sub local area network the authentication client that sends the request message belongs to and the priority of the authentication client.

The first allocating module 6022 is to, when the detecting execution module 6021 has detected that the Portal client is of a high priority, determine a sub local area network token bucket corresponding to the sub local area network to which the Portal client that sends the request message belongs, and to take the high priority token bucket in the determined sub local area network token bucket as a token bucket for allocating tokens, and then to allocate a token to the Portal client that sends the request message and to redirect the request message to the Portal server.

The second allocating module 6023 is to, when the detecting execution module 6021 has detected that the Portal client is not of a high priority, determine a sub local area network token bucket corresponding to the sub local area network to which the Portal client that sends the request message belongs, and take the low priority token bucket in the determined sub local area network token bucket as a token bucket for allocating tokens, and to allocate a token to the Portal client that sends the request message and redirect the request message to the Portal server; and if there is no token in the token bucket for allocating tokens, to allocate further a token in the shared token bucket to the Portal client that sends the request message and redirect the request to the Portal server, and to discard the request message if there is no token in the shared token bucket for allocating tokens.

The recovering module 6024 is to recover the allocated token after a successful authentication of the Portal client that sends the request message.

Furthermore, the detecting execution module 6021 comprises a configuration information acquiring sub-module 60211 and a detecting sub-module 60212.

The configuration information acquiring sub-module 60211 is to provide the configuration information of the authentication client of a high priority and the authentication client of a low priority to the detecting sub-module 60212. The configuration information comprises: an IP address network field corresponding to each of the sub local area networks and the corresponding priority of each IP address in each IP address network field when the authentication client is identified with an IP address; and a corresponding MAC address network field of each of the sub local area networks and the corresponding priority of each MAC address in each MAC address network segment when the authentication client is identified with an MAC address.

The detecting sub-module 60212 is to determine which sub local area network a Portal client that sends the request message belongs to and the corresponding priority of the Portal client according to the IP address and configuration information of the Portal client; or, to determine the sub local area network to which a Portal client that sends the request message belongs and the corresponding priority of the Portal client according to the MAC address and configuration information of the Portal client.

The above-mentioned example is only an example of the authentication access apparatus, while in other application scenarios, there may be the following circumstances.

First, the setting execution module 6011 shown in FIG. 6 can set one high priority token bucket and two low priority token buckets in each sub local area network token bucket. On this basis, the second allocating module 6023 shown in FIG. 6 is to determine the sub local area network token bucket corresponding to the sub local area network to which the Portal client that sends the request message belongs when the detecting execution module 6011 detects that the Portal client is not of a high priority, and to search the determined sub local area network token bucket for a low priority token bucket which corresponds to the level of the authentication client that sends the request message and to take the found low priority token bucket as the token bucket for allocating tokens, and then to allocate a token to the Portal client that sends the request message and redirect the request message to the Portal server; if there is no token in the token bucket for allocating tokens, then first further judging whether there is a token in other low priority token buckets whose level is lower than that of the found low priority token bucket, if yes, then to preempt one token from the other low priority token buckets for the unauthenticated authentication client that sends the request message and redirect the request message to the authentication server; otherwise, to allocate a token from the shared token bucket to the Portal client that sends the request message and redirect the request message to the Portal server, and then to discard the request message if there is no token in the shared token bucket.

Second, the setting execution module 6011 shown in FIG. 6 can set one high priority token bucket and more than two low priority token buckets in each sub local area network token bucket, but no shared token bucket is set in the local area network token bucket. On this basis, the second allocating module 6023 shown in FIG. 6 is to determine the sub local area network token bucket corresponding to the sub local area network to which the Portal client that sends the request message belongs when the detecting execution module 6021 detects that the Portal client is not of a high priority, and then to search the determined sub local area network token bucket for the low priority token bucket corresponding to the level of the authentication client that sends the request message, and then to take the found low priority token bucket as the token bucket for allocating tokens, then to allocate a token to the Portal client sending the request message and redirect the request message to the Portal server; if there is no token in the token bucket for allocating tokens, to judge whether there is a token in other low priority token buckets whose level is lower than that of the found low priority token bucket, if yes, then to preempt one token from the other low priority token buckets for the unauthenticated authentication client that sends the request message and redirect the request message to the authentication server; otherwise, to discard the request message.

It can be seen that when the setting execution module 6011 sets more than two low priority token buckets in each of the sub local area network token buckets, it is allowed to preempt tokens for Portal clients corresponding to low priority token buckets of a certain level from low priority token buckets of a lower level in the same sub local area network token bucket.

Moreover, in order to make sure that not all the tokens in the low priority token buckets of a lower level are preempted, a token preempting threshold may be set, thus the second allocating module 6023 will be further to judge, when there is a token in the other low priority token buckets, whether the number of tokens preempted from the other low priority token buckets has reached the set threshold, and the operation of preempting a token from the other low priority token buckets can be continued only if the number does not reach the set threshold.

As described in more detail below, each of the above mentioned units or modules in FIGS. 5 and 6 may be implemented as machine readable instructions executable by one or more processors of the device. Alternatively, some or all of the units or modules may be implemented as one or more hardware modules comprising logic circuitry to perform the above described operations.

The examples and embodiments described above may be implemented by hardware, software or firmware or a combination thereof. For example the various methods, processes and functional units or modules described herein may be implemented by a processor (the term processor is to be interpreted broadly to include a CPU, processing unit, ASIC, logic unit, or programmable gate array etc.). The processes, methods and functional units may all be performed by a single processor or split between several processers. In a common implementation the units or modules may be implemented as machine readable instructions executable by one or more processors. Further the teachings herein may be implemented in the form of a software product. The computer software product is stored in a storage medium and comprises a plurality of instructions for making a computer device (which can be a personal computer, a server or a network device, etc.) implement the method recited in the examples of the present disclosure.

Those skilled in the art can understand that the modules or units in the apparatus in the examples can be arranged in the apparatus as described in the embodiment, or can be alternatively located in one or more apparatuses different from that, in the example. The modules in the aforesaid example can be combined into one module or further divided into a plurality of sub-modules.

Accompanying figures are only schematic diagrams of examples, the modules, units or process block in the figures are not indispensable.

Those skilled in the art may understand that the modules in the device in embodiment may be adaptively varied and disposed in one or more devices different from the embodiment. The modules or units in the embodiment may be combined into one module or unit, and further may be divided into multiple sub-modules or sub-units.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the processes or units of any method or device so disclosed, may be combined in any combination, except combinations where at least some of such features and/or processes or units are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed in one example only of a generic series of equivalent or similar features. 

1. A method for controlling a traffic of an authentication sever, said method comprising: setting a local area network token bucket including a high priority token bucket and a low priority token bucket for a local area network, wherein the number of tokens in said local area network token bucket is equal to or less than the number of request messages which can be processed by the authentication server; detecting whether an authentication client in said local area network that sends a request message is of a high priority or not; allocating a token from the high priority token bucket to the authentication client that sends the request message and redirecting the request message to the authentication server, when the authentication client has been detected to be of a high priority; allocating a token from the low priority token bucket to the authentication client that sends the request message and redirecting the request message to the authentication server, when the authentication client has been detected to be not of a high priority; and recovering the allocated token after a successful authentication of the authentication client that sends the request message.
 2. The method as claimed in claim 1, wherein said local area network comprises more than one sub local area network; the setting a local area network token bucket including a high priority token bucket and a low priority token bucket for the local area network further comprising: setting a sub local area network token bucket corresponding respectively to each sub local area network in the local area network token bucket; and setting a high priority token bucket and a low priority token bucket in each sub local area network token bucket, wherein the number of tokens in the high priority token bucket is not more than the number of the authentication clients which are configured to have the high priority in the sub local area network, and the sum of the numbers of tokens in the high priority token bucket and the low priority token bucket is equal to the number of tokens in the sub local area network token bucket.
 3. The method as claimed in claim 2, wherein the detecting whether an authentication client that sends a request message in said local area network is of a high priority or not further comprises: detecting which sub local area network the authentication client that sends the request message belongs to and the priority of the authentication client; when the authentication client has been detected to be of a high priority, determining the sub local area network token bucket corresponding to the sub local area network to which the authentication client that sends the request message belongs before allocating a token, and taking the high priority token bucket in the sub local area network token bucket as the token bucket for allocating tokens; when the authentication client has been detected to be not of a high priority, determining the sub local area network token bucket corresponding to the sub local area network to which the authentication client that sends the request message belongs before allocating a token, and taking the low priority token bucket in the determined sub local area network token bucket as the token bucket for allocating tokens; and when the authentication client has been detected to be not of a high priority, discarding the request message if there is no token in the token bucket for allocating tokens.
 4. The method as claimed in claim 3, wherein said setting a high priority token bucket and a low priority token bucket in each sub local area network token bucket further comprises: setting one high priority token bucket and more than two low priority token buckets in each sub local area network token bucket, wherein different low priority token buckets correspond to authentication clients which are configured to have different levels of low priorities in the sub local area network, and the sum of the numbers of tokens in the high priority token bucket and in all the low priority token buckets is equal to the number of tokens in the sub local area network token bucket; and said taking a low priority token bucket in the determined sub local area network token bucket as the token bucket for allocating tokens further comprising: searching the determined sub local area network token bucket for a low priority token bucket which corresponds to the level of the authentication client that sends the request message and taking the found low priority token bucket as the token bucket for allocating tokens.
 5. The method as claimed in claim 4, wherein when the authentication client has been detected to be not of a high priority, and if there is no token in the token bucket for allocating tokens, then first judging whether there is a token in other low priority token buckets whose level is lower than that of the token bucket for allocating tokens, if yes, then preempting one token from said other low priority token buckets for the authentication client that sends the request message and redirecting the request message to the authentication server, otherwise, discarding the request message.
 6. The method as claimed in claim 5, wherein when there is a token in said other low priority token buckets, further judging whether the number of tokens preempted from said other low priority token buckets has reached a set threshold, if yes, discarding the request message; otherwise, preempting one token from said other low priority token buckets.
 7. The method as claimed in claim 3, wherein while the setting sub local area network token buckets corresponding respectively to each the sub local area network in a local area network token bucket, further setting a shared token bucket in the local area network token bucket, wherein the, sum of the numbers of tokens in each of said sub local area network token buckets and in said shared token bucket is equal to the number of tokens in said local area network token bucket; and before said discarding the request message, further judging whether there is a token in said shared token bucket, if yes, allocating one token from the shared token bucket to the authentication client that sends the request message and redirecting the request message to the authentication server, otherwise, discarding the request message.
 8. The method as claimed in claim 3, wherein said detecting which sub local area network the authentication client that sends the request message belongs to and the priority of the authentication client further comprises: determining a sub local area network to which the authentication client that sends the request message belongs and the corresponding priority of the authentication client according to the IP address and configuration information of the authentication client; or, determining which sub local area network the authentication client that sends the request message belongs to and the corresponding priority of the authentication client according to the MAC address and configuration information of the authentication client, wherein said configuration information comprises: an IP address network field corresponding to each of said sub local area networks and the corresponding priority of each IP address in each IP address network field when the authentication client is identified with an Internet Protocol (IP) address; and a corresponding MAC address network field of each of said sub local area networks and the corresponding priority of each MAC address in each MAC address network field when the authentication client is identified with an media access control (MAC) address.
 9. An authentication access apparatus, the authentication access apparatus comprising: a token bucket setting unit and a detecting and allocating unit; wherein said token bucket setting unit is to set a local area network token bucket including a high priority token bucket and a low priority token bucket for a local area network, wherein the number of tokens in said local area network token bucket is equal to the number of request messages which can be processed by an authentication server; and wherein said detecting and allocating unit is to detect whether an authentication client that sends a request message is of a high priority or not, and, when the authentication client has been detected to be of a high priority, to allocate a token from the high priority token bucket to the authentication client that sends the request message and redirect the request message to the authentication server; and when the authentication client has been detected to be not of a high priority, to allocate a token from the low priority token bucket to the authentication client that sends the request message and redirect the request message to the authentication server; and to recover the allocated token after a successful authentication of the authentication client that sends the request message.
 10. The apparatus as claimed in claim 9, wherein said token bucket setting unit comprises: a setting execution module and a storage module; wherein said setting execution module is to set a local area network token bucket, wherein the number of tokens in said local area network token bucket being equal to the number of request messages which can be processed by the authentication server; to set sub local area network token buckets corresponding respectively to each sub local area network in the local area network token bucket; to set a high priority token bucket and a low priority token bucket in each sub local area network token bucket, wherein the number of tokens in the high priority token bucket is equal to the number of authentication clients which are configured to be of a high priority in the sub local area network and the sum of the numbers of tokens in the high priority token bucket and low priority token bucket is equal to the number of tokens in the sub local area network token bucket; and said storage module is to store the result of setting of said setting execution module.
 11. The apparatus as claimed in claim 10, wherein said detecting and allocating unit further comprises: a detecting execution module, a first allocating module, a second allocating module and a recovering module; wherein said detecting execution module is to detect which sub local area network the authentication client that sends the request message belongs to and the priority of the authentication client; wherein said first allocating module is to, when said detecting execution module has detected that the authentication client is of a high priority, determine a sub local area network token bucket corresponding to the sub local area network to which the authentication client that sends the request message belongs, and take the high priority token bucket in the determined sub local area network token bucket as a token bucket for allocating tokens, and to allocate a token to the authentication client that sends the request message and redirect the request message to the authentication server; wherein said second allocating module is to, when said detecting execution module has detected that the authentication client is not of a high priority, determine the sub local area network token bucket corresponding to the sub local area network to which the authentication client that sends the request message belongs, and take the low priority token bucket in the determined sub local area network token bucket as a token bucket for allocating tokens, and to allocate a token to the authentication client that sends the request message and redirect the request message to the authentication server, and to discard the request message if there is no token in the token bucket for allocating tokens; and wherein said recovering module is to recover the allocated token after a successful authentication of the authentication client that sends the request message.
 12. The apparatus as claimed in claim 11, wherein said setting execution module sets one high priority token bucket and more than two low priority token buckets in each sub local area network token bucket; and said second allocating module is further to search the determined sub local area network token bucket for a low priority token bucket corresponding to the level of the authentication client that sends the request message and take the found low priority token bucket as the token bucket for allocating tokens.
 13. The apparatus as claimed in claim 12, wherein said second allocating module is to, when there is no token in the token bucket for allocating tokens, first judge whether there is a token in other low priority token buckets whose level is lower than that of the token bucket for allocating tokens, if yes, to preempt one token from said other low priority token buckets for the authentication client that sends the request message and redirect the request message to the authentication server, otherwise, to discard the request message.
 14. The apparatus as claimed in claim 13, wherein said second allocating module is further to, when there is a token in said other low priority token buckets, first judge whether the number of tokens preempted from said other low priority token buckets has reached a set threshold, if yes, to discard the request message, otherwise, to preempt one token from said other low priority token buckets.
 15. The apparatus as claimed in claim 11, wherein said setting execution module is further to set a shared token bucket in said local area network token bucket, wherein the sum of the numbers of tokens in each of said sub local area network token buckets and in said shared token bucket is equal to the number of tokens in said local area network token bucket; and said second allocating module is further to judge whether there is a token in said shared token bucket before discarding the request message, if yes, then to allocate a token from the shared token bucket to the request message and redirect the request message to the authentication server, otherwise, to discard the request message.
 16. The apparatus as claimed in claim 11, wherein said detecting execution module comprises a configuration information acquiring sub-module and a detecting sub-module; wherein said configuration information acquiring sub-module is to provide configuration information of said authentication client of a high priority and said authentication client of a low priority to the detecting sub-module; and said configuration information comprises: an IP address network field corresponding to each of said sub local area networks and the corresponding priority of each IP address in each IP address network field when the authentication client is identified with an Internet Protocol (IP) address; and a corresponding MAC address network field of each of said sub local area networks and the corresponding priority of each MAC address in each MAC address network field when the authentication client is identified with an media access control (MAC) address; and wherein said detecting sub-module is to determine which sub local area network the authentication client that sends the request message belongs to and the corresponding priority of the authentication client according to the IP address and configuration information of the authentication client; or, to determine which sub local area network a authentication client that sends the request message belongs to and the corresponding priority of the authentication client according to the MAC address and configuration information of the authentication client. 